Grinding wheel dressing attachment



Nov. 24, 1942. J. E. O'NEILL GRINDING WHEEL DRESSING ATTACHMENT esheets-sheet 1 md oct. 29, 1940 Jagt/LE lli Nov.l24, 1942.Y J. s.oNr-zlm..

l GRINDING WHEEL DRESSING 'ATTACHMENT med oct. 29, 1940. e sheets-sheet2 lNvENToR J cyuZ/ZOMIZZ .BY ATTORNEY i Nov. 24, 1942. J. E. o'NElLL2302312 GRINDING WHEEL DRESSING ATTACHMENT Filed Occ.4 2 9. 1940 6Sheets-Shet 3 a l' l l INVENTOR ATTORNE\2 Nv.24,.*1942. J. EofNElLL2,302,112

GRINDING WHEEL DRESSING ATTACHMENT /7 Z7 zal 23.22 25 Y Y 45 47 442/2 z/0 7 .9 f.

Bmw YJoggp/Lt Ojvw v ATTORNE w. 1942. I J. aloNElLL E I 52,302,712

GRINDING WHEEL DRESSING ATTACHMENT Filed Oct. 29, 1940 6 Sheets-Sheet 5l l J6 20 1 0 i759 M ff 7 l' "l1-"l A l J0 F 10 6' 20 f l 9 4 2 5 o" A 7f L 3 INVENTOE l JWEZOMBL'U Nov. 24, 1942. J. E. o'NElLl.

GRINDIG WHEEL DRESSNG lATTACHMENT \t. 29, 1940 e sheets-sheets ATTQRNEPatented Nov. 24, 1942 OFFICE Joseph E. ONeill, Kenilworth, Md.

Application October 29, 1940, Serial No. 363,323

. 11 mams. (ci. 12s- 11) (Granted under the act of March 3, 1883, 'as yThis invention relates to an attachment for use on grinding machines,for' the purpose of dressing the grinding wheels thereof to a desiredshape.

,It is an object of this invention to provide a dressing attachmentwhich maybe quickly and easily adjustable to generate any desiredproille on a grinding wheel. f

It is another object of this invention to provide a dressing attachmentwhich will generate convex and concave grinding wheel profiles withequal facility.

It is a further object of this invention to'provide a dressingattachment which will generate in one continuous operation a grindingwheel profile. composed of both straight and arcuate portions withoutany break in the-proflle outline.

Referring now to the drawings:

Fig. 1 is a front elevational view of a portion ofi a grinding machineshowing an attachment conforming to one embodiment of the invention.

Fig. 2 is a plan view, somewhat enlarged, show- ,ing the attachment ofFig. 1 mounted before the grinding wheel and upon the magnetic chuck ofthe grinding machine, shown fragmentarily;

Fig. 3 is an end elevation of the attachment, looking from the right inFig. 1, partlyY in section, vshown mounted upon a fragment of thegrinding machine; y

Fig. 4 is a vertical, longitudinal, sectional view through theattachment taken along the line 4-4 of Fig. 2; p

Fig. 5 is a horizontal, longitudinal, sectional view taken along theline 5-5 of Fig. 4; l

Figs. 6 and 6 A are fragmentary, vertical, longitudinal, sectional viewstaken along the line 6-6 of Fig. 2, showing the details of the slidecentering mechanism of Fig. 3;

Fig. 7 is an enlarged detail, vertical, sectional view taken along theline I-'I of Fig. 2 showing the centering detent pin in engagement asrequired for setting-up adjustments to be considered later;

Fig. 8 shows diagrammatically and Vby legend the method of setting therotary limitsto'ps by use of the gauge block system;

Fig. 9 is a vertical longitudinal sectional View of a second embodimentof the dressing attachment utilizing a spring influenced cam arrangementin the manner of an overloading clutch;

Fig. 10 is a fragmentary sectional -view taken along the line I0-I0 ofFig. 9 showing the rack gear arrangement; Fig. 11 is a verticallongitudinal sectional view amended April 30, 1928; 370 O. G. 757) alongthe line II-Il of Fig. 9-showing enlarged details of the cam-clutchscapement;

Fig. 12' is a schematic diagram showing the arrangement and operation ofthe gearing and the paths of movement ofthe tool, the turntable,

and the tool carriage for generating convex pro-.

files; and,

Fig. 13 is a schematic diagram similar to that of Fig. 12 but withreference to the generation of concave profiles.

The embodiment of the device depicted in Figs.

thrust in either an upward or downward dlrecl tion. This assembly iscomposed of two series of bearing balls I0 and Il confined in parallelYball races formed in the outer faces of two abutting kinner cones I2 andI3 and in the ,innerfaces of two abutting outer cones I4 and I5. Theareas of engagement of the raceways formed in cones I2 and I4 with theballs I 0 are oset from the horizontal as shown in Fig. 4 so. thatdownward movement of the turntable is prevented. The areas of engagement.of the raceways formed in cones I3 and I5 with the balls II are offsetin the opposite manner and thus prevent upward movement of theturntable.

I Concentrically and rotatably mounted in the depending portion 9 ofturntable 8 is a. vertical spindle 2 terminating at its upper end in abevel gear 3 and having a worm gear 4 keyed on its lower end. The wormgear 4 is driven by a worm 5 keyed on a shaft 6 mounted horizontally inthe base and rotated by a handwheel 1.

Formed above the upper surface of turntable 8 is a T-shaped post I6.Formed along its top is a dovetailed guide I'I. Slidably mounted in thedovetailed guide is a slide I8 carrying a pedestal I9 which terminatesin a tool-head 2li. Rising above the surface of the turntable d1-ametrically opposite the post I6 is a support 2|.

Passing through both post I6 and vsupport 2l is a shaft 22I having keyedthereto a pair of bevel pinions 23 and 24, either of which, bylongitudinally moving said shaft, may be brought into meshingrelationship to said gear 3. The shaft 2-2 carries a pinion 25 splinedthereto andlocated in a slot 26 in post I6. Near the other end of theshaft a sleeve 21, mounted for rotation relative thereto but securedagainst endwise motion with respect thereto is provided withalongitudinal slot 28 into which extends a dogpoint set and has extendingdownwardly from its upper 1 inner surface, an extension 30 havingsecured to its lower edge a rack 3l wh'ich meshes with the pinion 25.Attached to the ends of the arms of the T-shaped post i6 are twosupports 32, 33 as shown in Fig. 3. Secured between and passing throughthe upperends of these supports is a bolt 34. The central portion of thebolt is of larger diameter than the end portions, as shown by Figs. 6and 6a, and this portion of the bolt passes through a, bore formed inextension 30. A pair of sleeves 35 and 36 fit over the reduced endportions thus increasing their diameter to a size greater than that ofthe central portion of the bolt. A spring 31 surrounds the centralportion of the bolt and its ends abut washers 38 and 39 Y which are oflarger diameter than abutting sleeves 35 and 36. A pair of threadedcollars 40 and 4I are fitted into the ends of the bore in extension 30,their inner ends being ush with the inner ends of sleeves 35 and 36. Thecollars 40 and 4I are slidable over sleeves 35 and 35.

Figs. 6 and 6a illustrate what happens when relative movement betweenslide I8 and post i6 takes place. In Figs. 6 and 6a the slide I8 hasbeen moved to the left with respect to post i6. It will be noted thatthe spring 31 has been compressed by the motion of collar 4| and washer39 to the left, while washer 38 at the left end of the bolt is forced toremainin its initial position by sleeve 35.

The tool head 23 is formed with a horizontal bore in which is mounted acylindrical diamond holder 42 carrying diamond 43 in its end.

In Figs. 1, 2, 3 and 4 the attachment is shown mounted upon the magneticchuck of a conventional surface grinding machine. It may, however, beused with cylindrical grinding machines. Since the attachment has nomeans of its own for being adjusted before the grinding wheel use ismade of the regular grinding wheel table and carriage adjustmenthandwheels and screws,

marked J, K and L respectively of Fig. 1.

These mechanlsmsare used just as one would use I them for locating work.with respect to the grindlng wheel M. The diamondr tool however, is

located on the right of the grinding wheel, rather i" than below it. asisusually the case with the work,

and it is therefore necessary to adjust the vguard N around to the left,by turning screw P of Fig. 2 to loosen or tighten theclamp-sleeve of theguard.

Inl order to generate grinding wheel profiles composed -of arcs andstraight lines tangent thereto, it is necessary that the turntablerotate about its axis for part of the time and then be arrested whilestraight line motion of the diamond continues. This is accomplished bythe provision of stops as follows:

As best shown in Fig.- 3, the base l has formed on its upper surface acollar 44, having a vertical bore therein, which' is provided at itsupper end with a tapered hole to take with a snug fit the -tapered end46 of a detent 45 which extends through turntable 8 and is springpressed downwardly but may, by suitable turning in its bore, be held ina raised position out of engagement with collar 44. When the detent isin engagement withvthe collar the tool'head 2liv is so positioned thatthe point of the diamond 43 will lie in the center plane of the grindingwheel, or the turntable may be said to be in its neutral or centeredposition. The under side of the turntable is provided with an annulargroove 41 having tapered side Walls, for the reception of a pair ofadjustable stops 43 and 49 each having a dovetailed portion which iscarried bygroove 41 and may be clamped in position by a. nut 5l.Coacting with the adjustable stops is a fixed stop 52 carried bythe basel and located with its center line in the plane containing the axis ofthe turntable and passing through the center of the grinding wheel.

The diamond holder 42, as shown in Fig. 4, has 'a squared end 53 and athreaded head 54 which is threaded into bore 55 of tool head 20. A setscrew 5B serves to hold the holder 42 in adjusted position. The oppositeend of the head 20 is supplied with a hardened ball 51 which serves asan accurate starting point for measuring the distance E which remainsconstant and the variable distance X. The radius C ofthe generated arcmay bc found by subtracting the measured distance'X from the knowndistance E.

The operation of the attachment is as follows: The position of thediamond must rst be adjusted for a convex vor concave profile. Theposition of the point of the diamond with respect to the axis of theturntable determines whether rotation of the turntable will produce aconvex or a concave arc on the profile of the grinding wheel. If thepoint of the diamond is between the axis and the tool head 2li the arcwill be convex; if the axis is between the diamond point and thetool-head the arc will be concave.

For generating convex profiles the pinion 23 must be in mesh with gear3. This is accomplished by sliding shaft 22 to the right by means ofknob 53 pinned to its left handend as shown in Fig. 4. As shown in-Fig.5 a keeper pin 53 is carried by support 2| and when either of gears 23and 24 is engaged with gear 3, is spring pressed into one of tworecesses and 3| formed in sleeve 21 which surrounds'the left hand end-ofshaft 22, keeps pinion 23 or 24 in engagement and takes the thrust ofpinions 23 and 24.

The adjustable limit stops 43 and 43 are positioned at the points whereit is desired that arcuate motion of the diamond point cease andstraight line motion begin. Now, when handwheel 1 is turned in onedirection the spindle 2 driving through gear 3, bevel pinion 23 andpinion 25 will tend to move rack 3l in straight line motion. 1 However,the spring 31 will resist such motion and willprevent pinion23 fromrotating. The result will be that pinion gear 23 will be swept around asspindle' 2 turnsl and so will turntable 3, thus moving the diamond pointin an arc. This will continue until one or the other ofv stops 48 or 49contacts fixed stop 52. 'I'hen rotary motion of the turntable will ceaseand any further rotation of handwheel 1 will cause rack 3i to be movedrelative to the turntable, thus compressing spring 31 and moving thediamond point in a straight line tangent to the previous arcuate motion.When spring 31 is fully compressed so that collar 40 or 4i hits support32 or 33, further motion of the diamond point in that direction willcease. If the handwheel 1 is now turned in the opposite direction, thediamond point will retrace its straight line motion until the spring 31is back to expanded position and the engaged stops are freed, then thearcuate motion will be retraced until the other limit stop engages withstop 52 Whereupon straight line motion will again be commenced.

In order to generate concave'proles, the diatable, a slide mountedthereon and means guiding mond holder must be so adjusted that the pointof the diamond projects past the axis of rotation of the turntable by anamount equal to the radius of the desired concave arc. The change gearsmust also be shifted until gear 24 meshes with gear 3. Now, looking atFig. 4, a clockwise movement of worm will result in arcuate movement ofthe tool head 20 into the paper, with a corresponding arcuate movementof the diamondv point out fromv the plane of the paper, so 'long as thestops are not engaged. This movement is terminated by the-engagement ofstop 48 with fixed stop 52. Now continued motion of worm 5 in the samedirectionl will cause straight line illustrate the use of gauge blocksand show the formulas for deriving their length. 'I'he turntable is rstplaced in such a position as to allow detent 45 to enter the bore incollar 44. The tool is now in its neutral position as illustrated. Theblocks are now placed and the stops brought into abutting relationshipwith them and secured in position. Y l

A second embodiment of the invention is illustrated in Figs. 9, 10 and11.- In this embodiment the spring 31 has been omitted and movement ofrack 3l in response to rotation of gear 25 is therefore unopposed.'Surrounding spindle 2 is a two part sleeve.' The upper part 63 is xedto the turntable- 8 and the lower part 64 is splined to the spindle 2for limited longitudinal movement there along by means of a spline 65.The lower portion of the sleeve part 64 is reduced in diameter and aspring 66 surrounds the reduced portion. The abutting surfaces 3f-theits movement in opposite directions along a line normal to the radiusline of said table, a tool head carried by said slide, a wheel dressingtool carried by said tool` head and radially movable with respect tosaid table in such a manner that its cutting edge may be positioned oneither side of the center of said table, spring means tending to movesaid slide to a neutral position with regard to said radius line, a rackbar formed on the underside of said slide, a shaft mounted on said tableand extending along said radius line, said shaft being mounted forlimited axial movement, a gear .splined to said shaft and meshing withsaid rack bar, a driving gear concentric with the axis of said table, apair of pinions xed on said shaft and so positioned that one of themwill mesh with said drivingl gear when said shaft is posivtioned ateither endl of its allowed axial movement, means for rotating saiddriving gear, means for limiting the rotation of said table in eachdirectionv and means limiting the movement of said slide with respect toits guiding means.

2. In a grinding wheel dressing device, a rotary table, a slide mountedthereon, means guiding the movement of said slide inl oppositedirections along a line normal to a radius line of said table, a toolhead carried by said slide, a wheel dressing tool carried by said toolhead and radially movable with respect-to said table in such a mannerthat its cutting edge may b e positioned on either side of the center ofsaid talble, a shaft carried by said table and extending along saidradius, said shaft being' mounted for limited axial movement, a gearsplined to said shaft, a rack carried by said slide and meshing withsaid gear, a drivving gear located concentrically of said table a sleeveparts are cams and the action of the' spring 56 Will normally press thepart 64 up against the part 63 until contact throughout the opposing camfaces is secured. The strength `of spring 66 is such as normally toprevent relative movement between the cam faces and thus to cause amovement of spindle 2 to move turntable I around with it. However, whenthe stops 4hall'I movement of the turntable, continued movement ofspindle 2 causes the cam faces to move rela. tive to each other and thusallows movement of rack 3| relativeto the turntable. This movement maycontinue until separation of the 'sleeve parts 63 and 64 due to relativemotion between the cam faces, forces the lower end of part 64downjagainst the. upper surface of worm wheel 4. While thedisclosure ofthe invention has been restricted to two embodiments thereof it shouldbe understood that the invention is not limited thereto but only by thescope and limitations of the appended claims. V

vThe principle of this invention is applicable t other kinds of machinetool work, such as .profile grinding, profile milling and profileturning. d The invention described herein may be manufactured and/ orused by or for the Goverment of the United States of America forgovernmental purposes without the payment of any royalties thereon ortherefor.

I claim:

1. In agrinding wheel dressing device, a rotary pair of pinions fixed tosaid shaft and so positioned that one of them will mesh with said driv-4 ving gear when said shaft is positioned at either end of its allowedaxial movement, means for rotating said driving gear, means limiting therotation of said table in each direction and means yieldably biasingsaid driving gear to a position such that said slide lies in a neutralposition with respect to said radius.

3. In a grinding wheel dressing device, a rotary table, a slide mountedthereon, means guiding the movement of'said slide in opposite directionsalong a line normal toa radius line of said table, a ltool head carriedby said slide, a shaft carried by said table and extending along saidradius, said shaft beingmounted for limited axial movement,a gearsplined to saidshaft, a rack carried by said slide and meshing with saidgear, a driving gear located concentrically of said, table, a pair ofpinions xed kto said shaft and so positioned vthat one of them will meshwith said driving gear when said shaft is positioned at either end ofits vallowed axial movement, means yfor rotating said driving gearcomprising a shaft upon said parts being cam faces, and means limitingthe rotary movement of said table.

4. In a grinding wheel dressing device, a rotary table, a 'slide mountedthereon, means guiding the movement of the slide in opposite directionsalong a line normal to a radius line of said table, a tool head carriedby-said slide, a cutting. tool carried by said tool head and having acutting f biasing means being strong enough to prevent y movement ofsaid slide along said guiding means as long as said table is free torotate, and said biasing means and said slide moving means being soarranged as to apply the force of said slide moving means to said tablein a manner to rotate said table, means limiting the rotary movement ofsaid table and means for selectively applying the force of said slidemoving means to move said slide in either of its two possible directionsof -movement, upon the termination of the rotation of said table in agiven direction due to the action of said limiting means.

5. In a grinding wheel dressing device, a rotary table, a slide mountedthereon, means guiding said slide in opposite directions along a pathnormal to a radius line of said table, a tool head mounted on saidslide, a tool carried by said tool head-and having a cutting edgeextensible along a line passing through said axis, with said cuttingedge so positioned that said axis lies between it and said tool head,means operable to rotate said table in either direction means limitandtransferring said' force to said support in a direction to rotate saidsupport, means limiting the extent of the rotation of said support, and

means A*for shifting the direction of application to saidvmember of theforce generated by the movement of said driving element in a givendirection,

`whereby said member may be moved in either of its two possibledirections of movement by the movement of said driving element in onedirecradially with respect to said axis in a manner to position saidworking edge on either side of said axis, said tool head having formedthereon a' hardened accurately formed reference surface intersectingsaid line and lying normal thereto at the point of intersection, saidsurface facing in a direction opposite to said axis and being sopositioned that for all positions which said working edge may occupy onthe same side of said axis as said surface, said surface will be fartherfrom said axis than said edge, whereby the distance of. said edge fromsaid axis may be acing said rotation and means operable byV saidlimiting means, to apply the force of said rotating means to said slide,to move it in a direction opposite the direction of movement in which'said slide was moving, due to the rotation of said table, at thecessation of the rotation of said table.

6. In a grinding wheel dressing device, a rotary table, a slide mountedthereon, means guiding said slide in opposite directions along a pathnormal to a radius line of said table, a tool head mounted on saidslide, a tool carried by said tool head and having a cutting edgeextensible alonga line passing through said axis and adjustable oneither the same or the opposite side of said axis as said tool head,means operable to rotate said table in either direction within fixedlimits and means operable when said table has reached either of saidlimits to selectively apply the force of said rotating means tosaidslide to move it in a direction either opposite to or the same asthe direction of movement in which said'slide was moving, due to therotation of saidtable at..

the cessation of the rotation of said table.v

curately determined by measuring the distance of said working edge fromsaid surface vand comf paring it with the known distance of said surfacefrom said axis, substra'cting the larger of said distances from thesmaller.

9. In a grinding wheel dressing device, a support rotatable about anaxis, a tool head mounted upon said support and offset from said axis, atool held by said head, said tool having a working edge and beingextensible along a line extending radially with respect to said axis,and a hardened ball immovably held by said tool head, said ball being soheld that its center lies along said line, said tool lying nearersaidaxis than said ball, the surface of said ball farthest from said axisbeing '7.v Means for causing a particular elementvof a v mechanism tofollow a continuous path composed of either a convex or a concave arcand a straight line tangenty to an end of said arc, comprising a base, asupport mounted on said base for pivotal movement about an axis passingthrough Vsaid support, a member mounted on said support. guiding meansconstraining said member to move in a path normal to a radius of saidsupporting means, means holding said element said holding means beingmounted on said member for movement therewith and being adjustable tomove said element along a line passing through said axis to a positioneither on the some or on the opposite side of said axis as said holdingmeans, driving means comprising a driving element rotatable about saidaxis, means to apply the force generated by said driving element to saidmember in a direction tending to move it along its path, meansyieldingly restraining movement of said member available as a referencesurface for determining the distance of said cutting edge from saidaxis.

10,-Means for causing a particularelement of a mechanism to follow acontinuous path composed of a concave arc and a straight line tangent toanend. of said' are, said meansacomprising a support mounted for pivotalmovement about an a'xis passing therethrough, a member moimted on saidsupport, guiding means constraining said member to move in a path normalto a radius of said axis, means mounting said `element on said member insuch a manner that it is positioned on the opposite side of said axisfrom lsaid member,

. a driving means comprising a Arotating portion concentric with saidaxis. means transmitting the force generated by said driving means tourge.

said member along said path, yieldable means normally restraining saidmember from motion in response to said urging, said transmitting meansbeing so constructed as to thereupon apply said force to said supportinsuch a direction as tn rotate said support about said axis in adirection opposite to that along which said member was urged, and meanslimiting the rotation of said support, whereby-when said rotation isstopped by said limiting means said force will overcome said restrainingmeans and said member will be moved along said path in response to saidurging.

11. Means for causing a particular element of a mechanism to follow acontinuous path composed of concave arc and a straight line tangent toan end :of said arc, said means comprising a support mounted forpivotal. movement about an axis passing therethrough, 'a member mountedon said support, .guiding means constraining said member to move withrespect to said circuit in a path normal to a radius' of said axis,lmeans mounting said element on said member in such fa manner that it ispositionedl on the opposite side of said axis from said member, adrivingv means comprising a gear wheel concentric -with said axis, ashaft mounted on saidsupport and extending radially with respect to saidaxis, a rack formed on said member, a pair oi pinions secured to saidshaft, one of said pinions meshing aecomo lear wheel and lying betweensaid and said member, whereby rotation of said. gear wheel will urgesaid member along said path, `means restraining' the movement of saidmember in,l response to said urging, whereby they force generated bysaid rotation will rotate said other pinion and move said support in a'direction opposite to the direction in which said member was urged. fand means limiting the movement of said support, whereby when saidmovement has been stopped by said limiting means, said member be movedalong said path in response to said with said rack and the other meshingwith said l5.

. JOSEPH E.

